<template>
  <el-menu-item
    v-if="
      hasOneShowingChild(item.children, item) &&
      (!onlyOneChild.children || onlyOneChild.noShowingChildren)
    "
    :index="basePath"
  >
    <item
      :treeLevel="item.treeLevel"
      icon="el-icon-document"
      :title="onlyOneChild.menuName"
      :name="onlyOneChild.menuId"
    />
  </el-menu-item>

  <el-submenu v-else ref="subMenu" :index="basePath" popper-append-to-body>
    <template slot="title">
      <item
        :treeLevel="item.treeLevel"
        :icon="item.treeLevel == 1 ? item.icon : ''"
        :title="item.menuName"
        :name="item.menuId"
      />
    </template>
    <sidebar-item
      v-for="child in item.children"
      :key="child.menuId"
      :is-nest="true"
      :item="child"
      :base-path="resolvePath(child.menuId)"
      class="nest-menu"
    />
  </el-submenu>
</template>

<script>
import { isExternal } from "@/utils/validate";
import Item from "./item.vue";
export default {
  name: "SidebarItem",
  components: {
    Item,
  },
  props: {
    // route object
    item: {
      type: Object,
      required: true,
    },
    isNest: {
      type: Boolean,
      default: false,
    },
    basePath: {
      type: String,
      default: "",
    },
  },
  data() {
    // To fix https://github.com/PanJiaChen/vue-admin-template/issues/237
    // TODO: refactor with render function
    this.onlyOneChild = null;
    return {};
  },
  methods: {
    hasOneShowingChild(children = [], parent) {
      const showingChildren = children.filter((item) => {
        if (item.hidden) {
          return false;
        } else {
          // Temp set(will be used if only has one showing child)
          this.onlyOneChild = item;
          return true;
        }
      });

      // When there is only one child router, the child router is displayed by default
      if (showingChildren.length === 1) {
        return true;
      }

      // Show parent if there are no child router to display
      if (showingChildren.length === 0) {
        this.onlyOneChild = { ...parent, path: "", noShowingChildren: true };
        return true;
      }

      return false;
    },
    resolvePath(routePath) {
      if (isExternal(this.basePath)) {
        return this.basePath;
      }
      return routePath;
    },
  },
};
</script>
